The present invention relates to water flow control devices, and relates more particularly to such a water flow control device which has a control rod projecting out of the casing thereof and moved to drive the valve stem between the close position and the open position.
A variety of mechanical water flow control devices have been disclosed, and have appeared on the market. These mechanical water flow control devices commonly use a rotary handle or lifting lever to move a valve stem between the close position and the open position. Because the rotary handle or lifting lever must be moved in the reversed direction to close the valve stem after washing, the washed hand tends to be contaminated when turning the rotary handle or lifting lever. There are known various infrared-induced water flow control devices which eliminate the aforesaid problem. These water flow control devices automatically open the water passage upon the presence of the hand. However, these infrared-induced water flow control devices are commonly expensive and not durable in use. FIG. 5 shows a touch control type water flow rate control device according to the prior art, which comprises a casing defining a main water passage consisting of a vertical water passage and a horizontal water passage extending from the vertical water passage at one side, an upper valve and a lower valve installed in a vertical water passage, a water discharging port at the bottom end of the main water passage, a connecting rod connected between the upper valve and the lower valve, an auxiliary water passage defined inside the casing and having a top end connected to the top end of the main water passage above the upper water valve and a bottom end connected to the water discharging port, a relief valve to close the passage between the main water passage and the auxiliary water passage, and a handle pivoted to the casing. The handle has one end connected to the relief valve, and an opposite end extending out of the casing. The upper valve seals the vertical water passage. The lower valve seals the water discharging port. When the handle is touched by hand to open the relief valve, water is released from the vertical water passage to the auxiliary water passage, causing a reducing of the pressure of water above the upper valve. The upper valve and the lower valve are lifted due to a pressure difference. When the lower valve is lifted, water is allowed to discharge out of the water discharging port. When the handle is touched again to force the relief valve back to the close position, the pressure difference disappears, and the lower valve is lowered to close the water discharging port again. This structure of touch control type water flow control device is functional. However, because the handle has a certain length outside the casing, it tends to be triggered by an error to open the relief valve, causing water to be discharged out of the casing. Furthermore, this structure of water flow control device cannot be directly installed in the faucet of an existing water supply system.